Eskom has announced an updated timeline for the return of Unit 1 at the Koeberg Nuclear Power Station near Cape Town, which is undergoing the second phase of its long-term maintenance programme.
Initially expected back online by July 2025, the unit is now scheduled to return to service by the end of August 2025.
The delay follows detailed eddy current inspections of the steam generators, where minor defects were detected on four of the thousands of tubes inspected. Eskom said advanced automated repairs, carried out with the support of international and local experts, have since been successfully completed.
The utility also confirmed that all major maintenance activities, including the legally required 10-year Integrated Leak Rate Test (ILRT), were completed. The ILRT verified the reactor building’s structural integrity and leak-tightness, reinforcing Unit 1’s compliance with international safety standards.
“Our top priority is always the safety of our employees, the public and the environment,” said Eskom’s Group Executive for Generation, Bheki Nxumalo. “This maintenance will ensure decades of reliable, low-carbon power from Koeberg.”
Unit 2 remains fully operational, generating up to 946MW, and achieved an energy availability factor of 99.38% by June 2025. Together, Koeberg’s two units supply about 5% of South Africa’s electricity needs.
Eskom emphasised that the revised timeline for Unit 1’s return will not affect the risk of loadshedding. The utility’s Winter Outlook remains valid, with adequate capacity to meet demand if unplanned outages stay below 13 000MW.
Meanwhile, Eskom has made strides on other generation projects:
-On 6 July, the 800MW Medupi Unit 4 was brought back online after a long-term outage.
-Kusile Unit 6 was synchronised to the grid in March and will reach commercial operation by September.
-Kusile Units 1, 2 and 3, repaired and reconnected earlier this year, are now fully operational with flue gas desulphurisation systems.
Eskom said these milestones demonstrate its commitment to improving generation capacity and securing South Africa’s electricity supply.
Initially expected back online by July 2025, the unit is now scheduled to return to service by the end of August 2025.
The delay follows detailed eddy current inspections of the steam generators, where minor defects were detected on four of the thousands of tubes inspected. Eskom said advanced automated repairs, carried out with the support of international and local experts, have since been successfully completed.
The utility also confirmed that all major maintenance activities, including the legally required 10-year Integrated Leak Rate Test (ILRT), were completed. The ILRT verified the reactor building’s structural integrity and leak-tightness, reinforcing Unit 1’s compliance with international safety standards.
“Our top priority is always the safety of our employees, the public and the environment,” said Eskom’s Group Executive for Generation, Bheki Nxumalo. “This maintenance will ensure decades of reliable, low-carbon power from Koeberg.”
Unit 2 remains fully operational, generating up to 946MW, and achieved an energy availability factor of 99.38% by June 2025. Together, Koeberg’s two units supply about 5% of South Africa’s electricity needs.
Eskom emphasised that the revised timeline for Unit 1’s return will not affect the risk of loadshedding. The utility’s Winter Outlook remains valid, with adequate capacity to meet demand if unplanned outages stay below 13 000MW.
Meanwhile, Eskom has made strides on other generation projects:
-On 6 July, the 800MW Medupi Unit 4 was brought back online after a long-term outage.
-Kusile Unit 6 was synchronised to the grid in March and will reach commercial operation by September.
-Kusile Units 1, 2 and 3, repaired and reconnected earlier this year, are now fully operational with flue gas desulphurisation systems.
Eskom said these milestones demonstrate its commitment to improving generation capacity and securing South Africa’s electricity supply.